LED reflector lamps become more and more popular in a wide range of lighting applications. Typically a LED reflector lamp is an arrangement of a LED light source, heat sink, driver electronics, and most importantly a lens or reflector is being used to collect lights from the light source and direct them to form an illumination pattern defined mainly by the illumination beam angle it was designed for.
Current LED reflector lamps include spotlights and floodlights. Generally reflector lamps are classified as follows on the basis of the beam angle:
Spotlights: 4-19 degrees,
Floodlights: 20-35 degrees
Wide Floodlights: 36-49 degrees
Very Wide Floodlights: 50-120 degrees or more
Professional applications demand more tightened control of beam angles, for example to be set specifically at 8 degree, 24 degree, 36 degree, and 60 degree.
However it is often required to change the illumination area and the beam angles in many occasions such as retail stores or performance stages. For instance, it is necessary to carry inventory of all the different beam angles versions of the same reflector lamp in order to satisfy various application requirements of the user's, which results in a large inventory in stock and affects cash flow. In other cases, when the users want to change the lighting pattern utilizing lamp with a different illumination angle, they would either need to change out the existing lamps, or to change the lenses or the reflector kits with new replacements, which incur a lot of money, time and labor.
In the early days of stage lighting, the light sources were mainly incandescent, and the beam angle for the spotlights is changed by changing the relative distance between two or more lenses in front of the light source installed on a fixed reflector cup. U.S. Pat. No. 6,092,914 teaches such a design with two sets of lenses and a sliding beam angle adjustment mechanism using a rotating dial knob installed on the side of the lens assembly. Similar design can also be found in US patent application no. US2012/0287621A1 using LEDs as a light source.
Another design useful in torch lights for this purpose is to utilize an adjustment mechanism that allows a user to turn the lens assembly around its longitudinal axis. The grooves inside the lens assembly would then push the lens assembly further away from, or pull the lens assembly closer to the light source, hence the illumination angle of the torch light is being adjusted, which is taught, for example, in U.S. Pat. No. 7,261,438.
Apart from using the lens assemblies to effect the change of illumination beam angles, the use of multiple reflector assemblies could also achieve similar effects. US patent application no. US2010/0149820A1 teaches how the LED light beam angle is changed by extending or retracting the linear positions of a three section reflector assembly.
In some cases for a small change of the beam angle, it is only needed to move a single reflector toward or away from the light source along the reflector's central axis against its focal point. Adjusting the position of a lens, for example TIR (Total Internal Reflection) lens or Fresnel lens, towards and away in front of a LED light source, and along its central axis can also achieve the same results.
Push switches are well known in the mechanical field, which comprise an actuator mounted for reciprocal movement among alternate positions in a “push to change” manner. For example, U.S. Pat. No. 4,001,526A describes an “alternate action switch”. A variant of the push switch is designed as a “push latch” described in U.S. Pat. No. 5,984,381.
There is a need for adjusting reflector lamp conveniently to generate a light beam with variable beam angles.